'IS CONTENTS Introduction 1 PART I. EXAMINATION 1. II I 2 - History and General Examination 5 History 5 Terminology 8 Physical Examination 9 Examination of Specific Systems 13 Skin 13 The Fingertip and Nailbed 13 Muscles 15 Nerves 35 Circulation 45 Anatomy of the Bones and Joints 47 PART II. COMMON CLINICAL PROBLEMS 3. Lacerations 59 4. Common Fractures and Dislocations 63 Intra-articular Fractures 67 M ,| xvi CONTENTS CONTENTS xvii\ Bennett's Fracture Fifth CMC Fracture-Dislocation Boxer's Fracture Fracture of the Scaphoid 69 Undergrowth (Hypoplasia) 101 69 Congenital Constriction Band Syndrome 101 69 Generalized Skeletal Abnormalities * 71 Torn Ulnar Collateral Ligament of the 5. 71 Acquired Deformities Swan-neck Deformity Claw Hand Dupuytren's Contracture Rheumatoid Arthritis Degenerative Arthritis DeQuervain's Tenosynovitis Trigger Thumb and Trigger Finger Carpal Tunnel Syndrome Cubital Tunnel Syndrome Lateral Epicondylitis 6. Congenital Anomalies Failure of Formation of Parts Failure of Differentiation (Separation) of Parts Duplication Overgrowth (Gigantism] « • 7. Tumors 8. Infection Paronych ta ' 103 107 107 75 Felon 107 75 Purulent Tenosynovitis 107 78 Space Infections 109 78 Human Bite Infections 113 Mallet Finger Boutonnidre Deformity 1 1 MCP Joint of the Thumb 102 (Madelung's Deformity) • 69 The MCP Joint Dislocation 78 Appendix 1: Key to Abbreviations Used in 81 the Text 81 Appendix 2: Anatomy — Summary 86 Appendix 3: Clinical Assessment 86 Recommendations 115 117 121 89 Sensibility 121 89 Strength 121 91 Motion 122 95 Vascular Status 127 97 Suggested Readings 129 98 Index 133 99 100 101 \ I N T R O D U C T I O N This text is a core of information on the diagnostic history and physical examination of the normal, diseased, or injured hand. A method for thorough, systematic evaluation of the hand is presented so that with practice the reader can develop a routine for accurate examination to achieve a specific diagnosis. A brief introduction to specific conditions of the hand is given, followed by illustrations of the more common disorders. A limited description of certain lacerations, fractures, dislocations, and deformities is included. Specific treatment of each diagnosis is not discussed. The reader is referred to the standard texts and the current literature of hand surgery for detailed descriptions of treatment methods. ^ P A R T 1 E X A M I N A T I O N A 1 HISTORY A N D GENERAL EXAMINATION HISTORY Before examining the hands, a detailed history of the present problem should be obtained: A. What are the patient's age, occupation, and pursuits? WhicK_is ~tffe_dominanT~hand?y Has there been a previous hand impairment or injury? B. In trauma problems, the history should include the following specific information: 1. When did the injury occur and how much time has elapsed since the injury? 2. Where did the injury occur? Was it at work, home, or play? Under what conditions was the environment—clean or dirty? 3. How did the injury happen? What was the exact mechanism of the injury? (This helps to evaluate the amount of crush, contamination, blood loss, and level of injury to gliding parts.) What was the exact posture of the hand at the time of injury? ^ HISTORY AND GENERAL EXAMINATION A 6 THE HAND SURFACE ANATOMY (Palmar surface) JOINTS Distal ,'' interphalangeal (DIP) _. Proximal interphalangeal (PIP) Metacarpophalangeal '(MCP) MIDDLE (or long] INDEX SEGMENTS SMALL Distal phalanx CREASES Middle phalanx Distal interphalangeal Proximal interphalangeal Palmar digital Distal palmar. Proximal palmar Thenar Proximal phalanx Distal phalanx Proximal phalanx ULNAR BORDER RADIAL BORDER Wrist crease Figure 1 Surface anatomy of the hand DistoJ phaJanges Middle phaJanges Proximal phalanges Interphalangeal \ =s^\ ^Metacarpophalangealj N Carpometacarj)S] rjbasilar joint)j Metacarpals Hamate Pisi/orm TriquetrymL. Capitate Lunate _ Trapezoid^ f Trapezium? Scaphoid Figure 2 Skeleton of the hand and wrist 8 THE HAND 4. What previous treatment has been administered? C. In nontrauma problems, particular emphasis should be placed on: 1. When did the pain, sensory change, swelling, or contracture begin? In what sequence? Are these symptoms progressive? 2. How is function impaired in occupation, hobby, and activities of daily living? 3. Are other joints or tendons in this or other extremities painful in a similar way? 4. What activities make the pain worse? 5. At what time of day or night is the pain worse? D. A review of the past medical history and a review of systems should be obtained as part of the complete evaluation of the hand. TERMINOLOGY In order to avoid confusion it is important that standard terminology for structures of the hand be used. The hand and digits have a dorsal surface, a volar or palmar surface, and radial and ulnar borders (Fig. 1). The palm is divided into the thenar, mid-palm-, and hypothenar areasrThe names of the digits are-the thumbrindex,-middle-(long), r*ring, and", smaJMmgers. The thenar mass or eminence is that muscular area on the palmar surface overlying the thumb metacarpal. The hypothenar is that muscle mass on the palmar surface overlying the small finger metacarpal. Each finger has three joints: the metacarpophalangeal (MCP), the proximal interphalangeal (PIP), and the distal interphalangeal (DIP) joints (Fig. 2). Note the location of the finger MCP joints in the palm near the distal palmar crease, with the palmar-digital creases and finger webs at the level of the middle third of the proximal phalanges. HISTORY AND GENERAL EXAMINATION 9 The thumb has an MCP and only one interphalangeal (IP) joint. The carpometacarpal (CMC) joint of the thumb is particularly important because of its mobility. There are proximal, middle, and distal phalanges in the fingers and only a proximal and a distal phalanx in the thumb. The terminology used to describe the motion of the joints is illustrated in Figure 3. PHYSICAL EXAMINATION (see Ch. 2 for details) The entire upper extremity should be exposed and evaluated when the hand is examined. Assessment of active shoulder motion, elbow motion, and pronation and supination of the forearm is essential. Motion of these joints is necessary for proper positioning of the hand for function. Any discrepancy between active and passive mobility should be noted. When inspecting the hand, one should observe its color to assess circulation as well as the radial and ulnar pulses. The presence of swelling or edema should be noted as well as any abnormal posture or position. Skin moisture, localized tenderness, and sensibility must be evaluated. After injury to the hand there is often secondary stiffness and limited range of motion (ROM) of other joints of the extremity as well as the part involved. The range of both passive and active motion of the wrist, MCP joint, and IP joints of each digit should be measured and recorded. Grip and pinch strength should also be documented. The patient's ability to use the hand for simple function should be evaluated. Accurate recording of the findings of the examination of the hand is most important. A simple sketch of the hand with appropriate notations and measurements is often very helpful. ^ a HISTORY AND GENERAL EXAMINATION -11 \ 10 THE HAND FOREARM Ulnar deviation Radial j deviation Opposing thumb to finger FINGER Adduction Hyperextension Radial abduction Palmar a=ion Radial " ^ _ abduction tension Flexion Retroposition Figure 3 Terminology of hand and digit motion Anteposition fry-«-g A Y I 12 THE HAND Subsequent re-examination of the hand is just as important as the initial examination and should be done each time the patient returns for follow-up. Only by making appropriate serial recordings during the followup period can the examiner know for certain whether or not there is improvement in the patient's condition. 2 EXAMINATION OF SPECIFIC SYSTEMS SKTN The normal palmar skin is thick, tethered, irregularly surfaced, and moist, providing for traction and durability. Normal skin on the dorsum of the hand is thin and mobile, permitting motion of the various joints. The dorsum of the hand is the common site of edema, which may limit flexion. The examiner should note the presence or absence of swelling, wrinkles, color, moisture, scars, skin lesions, and surface irregularities. THE FINGERTIP AND NAILBED The fingertip is defined as that portion of the digit distal to the insertion of the extensor and flexor tendons into the base of the distal phalanx (Fig. 4). The tuft of the distal phalanx is well-padded by adipose tissue and covered by highly innervated skin which is tethered to the distal phalanx through a series of fibrosepta. The nailbed complex on the dorsum of the fingertip is important in providing additional stabilization of the palmar soft tissues against compression and shear forces (Fig. 4). The nailbed complex is also called the perionychium. The 13 EXAMINATION OF SPECIFIC SYSTEMS 14 THE HAND distal skin of the nailbed complex is referred to as the hyponychium. The cuticle or thin layer of skin bridging the nail plate to the dorsal skin of the nail complex is referred to as the eponychium. The nail plate arises from a pocket called the nail fold. The floor of the nail plate or nailbed is comprised of the proximal germinal matrix and distal sterile matrix. The semicircular division between these two areas is called the lunula. FINGERTIP AND NAIL COMPLEX Fingertip Insertion extensor tendon Nail fold Nail plate ^f%P /^ ^ ^ ^ 1 Insertion flexor tendon Hyponychiunry^^ {{fy^y: *®. •B FlbreEm^ Perionychium/nail complex Sterile matrix Lunula MUSCLES The muscles that power the hand may be divided into extrinsic and intrinsic muscles. The extrinsic muscles have their muscle bellies in the forearm and their tendon insertions in the hand. They are further divided into extrinsic flexor and extensor muscles. The flexors are on the volar surface of the forearm and flex the wrist and digits; the extensors are on the dorsum of the forearm and extend the wrist and digits. The intrinsic muscles have their origins and insertions within the hand. These muscles should be systematically evaluatedrAsk the "patient t6~"n£akeL aJ^"J^ind -< 's1xaighten. pu£]yj5ur fingers"^ this gives the examiner a general idea of the active ROM of the digits. However, it is necessary to examine each muscle group specifically. Specific extrinsic muscle testing Extrinsic flexor muscles figure 4 The fingertip and nail complex The function of the flexor pollicis longus (FPL) muscle, whose tendon inserts on the volar base of the distal / 16 THE HAND EXAMINATION OF SPECIFIC SYSTEMS 17 phalanx of the thumb, can be ^ ^ * Z * % * * & patient to "bend the tip of your thumb (Fig. 5). The muscle strength is tested against resistance supplied by ^T^Tdigitorum profundus (FDP) can brteatod by asking the patient to "bend the tip of your finger (Fig. 6). The PL? joint is stabilized in extension by the examiner as the distal joint is actively flexed. As each finger is examined, the muscle is tested against resis ance. Z h flexor digitorum superficialis (FDS) is individually tested by asking the patient to "bend yourfinger at the m ddle joint" (Fig. ^ T h ^ W ^ K S u s in extension by tHS. examiner so as to block profundus S u c t i o n (The profundus tendons of the ulnar three djats S S f c L n S n muscle belly, and thus independent flexion of any finger with the other digxts restrained in extension requires intact FDS musculotendinous functionTto that finger-) The procedure is repeated for each ^The flexor carpi ulnaris (FCU), flexor carpi radialis (FCR), and palmaris longus (PL) are evaluated by asking £ e patient to flex his wrist while the examiner palpates the tendons of these muscles. The FCU insert. m t e t h e pisiform and the FCR into the volar aspect <*****»* metacarpal. The PL inserts into the palmar fascia. The PL S i be noted to lie between the FCR radially and FCU Z a r l y on the volar surface of the wrist dunng this maneuver, especially if the thumb is simultaneously opposed to the small finger. Extrinsic extensor Figure 5 Testing for FPL musculotendinous function muscles The extrinsic extensor muscle bellies of the hand overlie the dorsum of the forearm, and their tendons pass over the - / IS THE HAND EXAMINATION OF SPECIFIC SYSTEMS 19 Figure 6 TestingforFDP musculotendinous Amotion Figure 7 Testing FDS musculotendinous function V Ii r ^ 20 THE HAND Figure 8 Arrangement of extensor tendons at the wrist into six compartments: dorsal and cross-sectional views ^ » EXAMINATION OF SPECIFIC SYSTEMS 21 Testing for Figure 9 EPB and APL musculotendinous function 22 THE HAND EXAMINATION OF SPECIFIC SYSTEMS 23 ^ dorsum of the wrist to insert in the hand (Fig. 8) They are arranged in six tendon compartments over the dorsum of tiie wrist A systematic examination of the tendons passing through each compartment is done. «f fJ™ f i *f d o f s ' 5 1 ^ i s t compartment contains the tendons of the abductor pollicis longus (APL), which inserts at the dorsal base of the thumb metacarpal, and the extensor polhas brevis QPB), which inserts at the dorsal base of the proximal phalanx of the thumb. These-are-evaluatriby S a D S , t ^ p a l f e f i r t 0 " b r i n 8 y o u r t h u m b 6utJp,thTsTde" Fig. 9). The examiner canpllpate'the'taut tendons over the radial side of the wrist going to the thumb. Tnersecofld dorsaDwrist compartment contains the tendons of the extensor carpi radialis longus (ECRL) and the extensor carpi radialis brevis (ECRB) muscles (Fig 10) They insert at the dorsal base of the index and middle metacarpals, respectively. These are evaluated by asking s L ^ T h 0 exa " ^1 a fiSt a n d b r i n g y™ ™ * back Ih^A ™ ™ can give resistance and palpate the tendons over the dorsoradial aspect of the wrist In the ^third-dorsal ^mst compartment, the extensor polhas longus (EPL) tendon passes around Lister's tubercle of the radius and inserts on the dorsal base of the distal phalanx of the, fcumb. This..murcle is evaluated-by placing the hand flat on the table and having the-patient lift only the thumb off the surface (Fig. i i ) Tteiouia..fasal^mst compartment contains the endons that are the MCP joint extensors of the fingers (Figs. 8 and 12). The extensor digtirum communis (EDO and the extensor mdicis proprius (EIP) muscle tendons are fintUS > S i ^ u n g * e P a t i e n t t 0 " ^ a i g h t e n your fingers and by observing MCP joint extension. The EIP tendon can be isolated on examination by asking the patient to "bring your pointing finger out Figure 10 Testing for ECRL and ECRB musculotendinous function ,Ai 24 THE HAND EXAMINATION OF SPECIFIC SYSTEMS 25 straight, with the other fingers bent in a fist." The EIP is acting alone to extend the index finger MCP joint (Fig. 12). The fifth dorsal wrist compartment contains the tendon of the extensor digiti minimi (EDM) (Fig. 12). This is evaluated by asking the patient to "straighten out your small finger with your other fingers bent in a fist." This extends the MCP joint of the small finger. The EDM is acting alone to extend the small finger. The sixth dorsal wrist compartment contains the tendon of the extensor carpi ulnaris (ECU), which inserts at the dorsal base of the fifth metacarpal (Fig. 13). This is evaluated by asking the patient to "pull your hand up and out to the side." The taut tendon can be palpated over the ulnar side of the wrist just distal to the ulnar head. Extrinsic extensor tightness. The extensor tendons can become adherent over the dorsum of the hand or wrist, limiting finger flexion. This can be tested by maintaining the wrist in neutral and passively extending the MCP joint and flexing the PIP joint. Normally, the PIP joint should flex. The test is then repeated with the MCP joint passively flexed. If the PIP joint will passively flex when the MCP joint is extended,_but will not flex readily with the MCP joint flexed, the adherent extrinsic extensors are "cHeckreining the simultaneous flexion of finger MCP and PIP joints. This is called "extrinsic extensor tightness." Intrinsic muscles Figure 11 TestingforEPL musculotendinous function The intrinsic muscles of the hand are those that have their origins and insertions within the hand. These are the thenar muscle group, adductor pollicis (AdP), lumbrical, and interosseous muscles and the hypothenar muscle group. A, 26 THE HAND EXAMINATION OF SPECIFIC SYSTEMS 27 Figure 12 Toting for.E^c;E^an7^ 'musc^oteadiffiys3uHrtiSn Figure 13 Testing for ECU musculotendinous function / 28 THE HAND EXAMINATION OF SPECIFIC SYSTEMS 29 Figure 14 Testingforthumb opposition Figure 15 (A&B) Fromerit's^sigriMs positive in hand B 'V] EXAMINATION OF SPECIFIC SYSTEMS 31 The thenar muscles The thenar muscles are the muscles covering the thumb metacarpal. They are the abductor pollicis brevis fAPB), opponens pollicis (OP), and flexor pollicis brevis (FPB). These muscles pronate or oppose the thumb (see Fig. 3) and can be evaluated by asking the patient to "touch the thumb and small fingertips together so that the nails are parallel" (Fig. 14). They can also be tested by asking the patient to place the dorsum of the hand flat on the table and raise the thumb up straight to form a 90° angle with the palm (see Fig. 3). At that time it is most important to palpate the thenar muscles to note if they contract. It is helpful to examine and compare the contralateral hand in a similar way to detect slight variations in muscle mass and function. The thenar muscles are usually innervated by the motor branch of the median nerve. In some patients, however, the thenar muscles may be partially innervated by the ulnar nerve. The adductor pollicis muscle Thumb adduction is separately tested by having the patient forcibly~holda_piece of paper .Bejwe_enthejthumb and radial side of the index proximal phalanx (Fig. 15). The muscle that-powers'this motion is the AdP, which is innervated by the ulnar nerve. When thisjnuscle is weak or nonfunctioning the thumb IP joint flexes with this maneuver (Froment's sign). In this evaluation the two hands must be compared. The interosseous and lumbrical muscles The interosseous and lumbrical muscles act on the fingers to flex the MCP joints and extend „the IP joints. The interosseous muscles also abduct and adduct the fingers. The interosseous muscles, which lie on either side of the finger metacarpals, are innervated by the ulnar nerve. They can be evaluated by asking the patient to "spread your fingers apart" while the examiner palpates the first dorsal interosseous to see if it contracts. In another test, with the hand flat on a table, the patient is asked to elevate (i.e., hyperextend the MCP joint with the IP joints straight) the middle finger and radially and ulnarly deviate it (Fig. 16). (This eliminates the extrinsic extensors, which some patients can use to mimic interossei finger abduction-adduction.) The hypothenar „ di muscles The hypothenar muscles —abductor digiti minimi (ADM), flexor digiti minimi (FDM), and opponens digiti minimi (ODM) —are evaluated as a group by asking the patient to "bring the small finger away from the other fingers" (Fig. 17). This muscle mass is palpated at that time, and a dimpling of the hypothenar skin is noted. Intrinsic muscle tightness. To test for finger intrinsic muscle tightness the MCP joint of the finger is held in extension (0° neutral position) while the PIP joint is passively flexed by the examiner (Fig. 18). The MCP joint is then flexed and the PIP joint is passively flexed in the same manner as before. If the PIP joint can be passively flexed with the MCP joint in flexion, but cannot be fully flexed when the MCP joint is extended, there is tightness of the intrinsic muscles. This is called "intrinsic tightness." 7T 7 . 32 THE HAND EXAMINATION OF SPECIFIC SYSTEMS 33 Figure 16 Testing for interosseous muscle function Figure 17 Testing for hypothenar muscle function ^ EXAMINATION OF SPECIFIC SYSTEMS 35 NERVES The hand is innervated by the median, ulnar, and radial nerves. Each of the three major nerves passes through a muscle in the forearm and each passes points of potential entrapment. All three nerves are involved in control of the wrist, fingers, and thumb. The median nerve The median nerve enters the forearm through the pronator teres muscle and innervates the following muscles: pronator teres, FCR, PL, FDS, radial part of the-FDFr-FPL1. airiH pr^natm- q n a H ^ n s (Fig. 19). The branch of the median nerve that innervates the latter three muscles is referred to as foe aniBriar.internssp.oiis pgfve! The median nerve travels distally through the forearm between the FDS and FDP muscles. It enters the hand through the carpal tunnel accompanied by the nine extrinsic flexor tendons of the digits. The thenar motor branch innervates the APB, the superficial belly of the FPB (variably so), and the OP. The common digital branches innervate the lumbrical muscles to the index and long fingers. The nerve then continues through the palm as sensory branches (described below). The ulnar nerve Figure 18 Intrinsic muscle tightness The ulnar nerve enters the forearm from the posterior to the medial epicondyle of the humerus and passes between EXAMINATION OF SPECIFIC SYSTEMS 37 36 THE HAND the two heads of the FCU (Fig. 20). It innervates the following muscles in the forearm: the FCU and the ulnar part of the FDP (usually to the ring and small fingers, occasionally to the long finger). It enters the hand at the wrist accompanied by the ulnar artery through a tunnel radial to the pisiform bone, ulnar to the hook of the hamate, volar to the deep transverse carpal ligament, and dorsal to the volar carpal ligament (Fig. 21). Tjiis tunnel is known as the uhiarjurmelor Guyon's canal. The ulnar nerve innervates the hypothenar muscles (the ADM, FDM, ODM), the seven interosseous muscles, the lumbrical muscles to the ring.and small fingers, and the AdP. It may innervate part or all of the FPB. ~t MEDIAN AND ANTERIOR INTEROSSEOUS NERVES Pronator teres Flexor carpi radialis Palmaris longus Flexor digitorum super/iciali! Flexor digitorum profundus Flexor pollicis longus Abductor pollicis brevis Flexor pollicis brevis Opponens pollicis Index lumbrical Middle lumbrical Prontator quadratus The radial nerve The radial nerve innervates me"tfic.eps',.^c6Tleus;'brac£joradialisTiand ECRL muscles above the elbow and ECRB as the nerve enters the forearm (Fig. 22). It passes through the supinator muscle to innervate the following muscles in the forearm: supinator, EDC, EDM, ECU, APL, EPL, EPB, and EIP. Thus its important motor function is to ^ innervate the muscles irrthe forearm that extend the wrist and MCP joints and tharabduct and extend the thumb. No intrinsic muscles in the hand are innervated by the radial nerve. Sensory branches of the nerves Pro/undus muscle is also supplied by ulnar nerve (see text) I Figure 19 Muscles innervated by the median and anterior interosseous nerves in the forearm and hand E L As it leaves the carpal tunnel, the median nerve divides into common sensory branches, which subsequently divide and innervate the palmar surface of the thumb, the index and middle fingers, and the radial side of the ring BXM^oNOFsrecmcsvsT*^ 38 THE HAND ULNAR NERVE Flexor carpi ulnaris Flexor digitorum pro/undus Adductor pollicis Deep head of Flexor pollicis brevis Palmaris brevis Abductor Opponens Digit minimi Flexor Little lumbrical Ring lumbrical Interossei * Pro/undus muscle is also supplied by median nerve (see text) Figure 20 Muscles innervated by the ulnar nerve in the forearm and hand fcL Ulnar Uln ar tunnel at wrist (Guyon's canal) contains CT, carpal tunnel Figure 21 artery and nerve; EXAMINATION OF SPECIFIC SYSTEMS 41 40 THE HAND RADIAL NERVE Triceps, long head _ Triceps, lateral head Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis — r I Anconeus Supinator 'I ' Extensor digitorum communis Extensor digiti minimi Extensor carpi ulnaris ____^_ Abductor pollicis longus , Extensor pollicis longus Extensor pollicis brevis Extensor indicis proprius Figure 22 Muscles innervated by the radial nerve in the forearm and hand finger (Fig. 23). Dorsal digital branches arise from the digital branches to innervate distal to the PIP joint, the dorsal aspect of the index and middle fingers, and the radial half of the ring finger. The median nerve also innervates the volar wrist capsule by the terminal branch of the anterior interosseous nerve. The ulnar nerve divides distal to the hook of the hamate into digital branches and innervateTthe smallTinger and ^^e-ulnar-fatdf^f-the^uiglinger (Fig. 23). The dorsal cutaneous branch oi the ulnar nerve enters the dorsal aspect of the hand over the small and ring metacarpals, the dorsum of the small finger, and dorso-ulnar half of the ring finger. The radial nerve supplies sensibility to the radialthree quarters of quarters m the mo dorsum u v . — of the hand and the dorsum of the ""thumb dorsum thumb (Fig. (Fig. 23). 23). It It also also supplies supplies sensibility sensibility to to the uie uwcu... -*t, -. j iAA\ fingers and the radial half nA m e oftheindex and middle fingers and the radial half of of the the ring finger as far distally as the PIP joint of each. It also innervates the dorsal wrist capsule by the terminal branch of the posterior interosseous nerve. Anatomic variation Anatomic variation should be considered in all cases where there has been an injury to a major nerve trunk. For example, there can be variations in the distribution of the ulnar and median nerves in the hand. The entire ring finger and ulnar side of the long finger may be innervated by the ulnar nerve, or the entire ring finger may be innervated by the median nerve. The palmar aspect of the thumb may be innervated by the radial nerve. The lateral antebrachial cutaneous nerve frequently overlaps the radial sensory nerve. 42 THE HAND EXAMINATION OF SPECIFIC SYSTEMS 43 Sensibility Sensibility is one of the most important functions of the hand. The insensible hand is poorly used even when the tendons and joints are normal. Normal skin should be slightly moist. Nerve dysfuncj tion causes-loss of sympathetic innervation-in-the-area of distribution,._and the sknrbecdmes'drvrThis isof clinical help in evaluating nerve dysfunction. Testing the finger with a sharp-pointed object, such as a pin, or thermal testing is not as critical and helpful as to test it for tactile gnosis by the moving and static two-point light touch djscrimination test {2FD). In this test the hand is positioned at rest on a flat firm surface and the patient closes his eyes. A device that measures innervation density, such as the Disk-Criminator or something as simple as a bent paper clip (Fig. 24) is used by beginning at a 6-mm distance between the prongs and proceeding higher or lower to determine the critical distance at which the patient indicates he can distinguish two points from one. An abnormal vahifefeE mm"static o r > 3 mm moving 2PD) indicates axonal loss and is the sensory system equivalent of wasting or atrophy in the motor system. This will occur with all nerve division and severe nerve compression. Vibratory perception is also lost with nerve division. With a mild or moderate degree of nerve compression, 2PD is preserved but sensory threshold changes, such as diminished perception of tuning fork stimulation and abnormal cutaneous pressure threshold (Semmes-Weinstein monofilament testing), occur. K Figure 23 -tributionof m a i o r n e r v e s . enervating the hand forsensory function D I I n evaluating" children for-traumatic nerve injuries,1 it may not be possible or practicjdJtojjgrfoim^PD test. In this situation, the use of the<^mmersion test^may be of benefit. The innervated glabrous skin of the hand will wrinkle on immersion in water for 5 to 10 minutes. 44 THE HAND EXAMINATION OF SPECIFIC SYSTEMS 45 Failure of the skin to wrinkle should raise the suspicion of an underlying nerve injury. CIRCULATION The radial and ulnar arteries supply the hand with blood. There is an arterial arch system that gives the hand a generous collateral blood supply (Fig. 25). The circulation of the hand is evaluated by noting the color of the skin and fingernails as well as the blanching and flush of the nailbed. The Allen test, used to determine patency of the arteries supplying the hand, is done as follows (Fig. 25): Figure 24 W p o t o domination testing 1. Compress the radial and ulnar arteries at the wrist. 2. Have the patient make a fist, open and close it several times to exsanguinate the hand, and then open the hand again into a relaxed position (avoid hyperextension at this point, as it will maintain blanching). 3. Release the radial artery only. If the palm and all five digits fill with blood, then the radial artery is patent, with good collateral flow into the ulnar artery system. 4. Repeat steps 1 and 2. 5. Release the ulnar artery only. If the entire hand flushes, then the ulnar artery is patent, with good flow into the radial system. 6. Normal fillinfi-time for the hand through either artery is "usually under. 5 seconds': A distinct difference in filling-time may suggest the dominance of one artery in providing circulation to the hand. V \/_ EXAMINATION OF SPECIFIC SYSTEMS 47 The Allen test can also be carried out on a single digit by expressing the blood out of the digit and occluding both digital arteries and then releasing the radial digital artery and noting the filling of the digit. The same procedure is carried out on the ulnar digital artery. This will help to evaluate the patency of each digital vessel to that finger. Another means of evaluating the arterial circulation of the hand is the Doppler probe. This device is readily available in most emergency rooms. The device can be used to confirm the presence of pulsatile flow and to map out the course of arteries through the hand. ANATOMY O F THE BONES AND JOINTS The skeleton of the hand consists of 27 bones, divided into three groups: the carpus, the metacarpal bones, and the phalanges (see Fig. 2). The carpus Figure 25 Allen test for arterial patency The eight carpal bones are divided into two rows. Those in the proximal row, beginning from the radial side, are the scaphoid-, lunate, tiiquetaim,_andpisiform. Those in the distal row are the trapeziurn, .trapezoid", capitate, and hamate. Much of the surface of the carpal bones is covered with cartilage, with roughened areas dorsally and volarly for ligamentous attachments and for entry of the vascular supply to the bone. Wrist flexion and extension as well as radial and ulnar deviation result from radiocarpal and intercarpal motion, whereas pronation and supination occur through the proximal and distal radioulnar joints. A 48 THE HAND EXAMINATION OF SPECIFIC SYSTEMS 49 Figure 26 ^ m a r view of st abi li2ingliganj( ^oftheradiocaxpaj,-^ The versatile ROM of the wrist and its stability are provided by a well-developed system of ligaments interconnecting the carpus and radius. These are most highly developed on the palmar aspect of the wrist. The important ligaments stabilizing the radial aspect of the carpus are the scapholunate interosseous ligament, radioscaphocapitate ligament, and radioscapholunate ligament (Fig. 26). On the ulnar side of the wrist, the primary stabilizer of the radioulnar joint is the triangular fibrocartilage, which originates from the dorso-ulnar corner of the distal radius and inserts at the base of the ulnar styloid (Fig. 27). The triangular fibrocartilage together with ulnolunate ligament and the ulnar collateral ligament comprise the ulnocarpal complex, which stabilizes the ulnar aspect of the carpus. A number of clinical tests can be used to evaluate the stability of the wrist. The piano key test evaluates the distal radioulnar joint. With one hand, firmly stabilize the distal radius; with the other hand, grasp the head of the ulna between the thumb and index fingers. Evaluate the freedom of motion in an anteroposterior plane as well as pain and crepitance. The scaphoid shift maneuver is performed by placing the examiner's thumb over the palmar aspect of the distal pole of the scaphoid. A constant pressure is maintained with the examining thumb as the wrist is moved from a position of extension, ulnar deviation to flexion, radial deviation, and back again. The presence of dorsal wrist pain or a clunk suggests possible instability of the scapholunate ligament. The lunotriquetral shear maneuver involves stabilizing the lunate between the thumb and index finger of one hand and the triquetrum between the thumb and index finger of the other hand. A shear stress is then created in an anteroposterior plane between these two bones. Discomfort in this area suggests the possibility of EXAMINATION OF SPECIFIC SYSTEMS 51 injury to the lunotriquetral interosseous ligament. In performing all of these manuevers, it is important to repeat the test on the uninjured, opposite wrist to provide a basis for comparison of the patient's symptoms. It is important to emphasize that the hand is not flat. It is based on a system of skeletal arches which must be maintained to preserve hand function (Fig. 28). Fixed and mobile units The metacarpals of the index and long fingers are firmly attached to the rigidly interconnected distal carpal row to form the "fixed" unit of the hand. From this are suspended the "mobile or adaptive" components of the h a n d — t h e thumb, the entire ring and small rays (including metacarpals), and the phalanges of the index and long fingers. The longitudinal arch is apparent in the lateral projection and is formed by the metacarpals and phalanges. There are two transverse arches: the proximal arch at the distal carpus and the distal arch at the metacarpal heads. The- thumb Tnetararpal artipiilates-withthetrapeziiim. forming the unique basilar idinfTwhiclTallows -for a wide latitude of thumb motion (Figs. 3 and 29). The MCP and IP joints of the fingers are stabilized on both sides by collateral ligaments and anteriorly- b y a; palrnar;fibrocarfilaginouC"volar" plate (Fig..30).The digital flexor tendons lie just anterior to-these"plates. The configuration of the metacarpal'heads causes their collateral ligaments to be slack in extension, permitting abduction, adduction, and circumduction. In flexion, however, MCP collateral ligaments become taut, providing stability to the joint. Articular configuration of the IP joints and the geometry of the collateral ligaments do not allow significant Figure 27 Stabilizing]^ ^ntsoftheulnocazpali,joint U i \ .A 1 i EXAMINATION OF SPECIFIC SYSTEMS 53 Figure 2a ^ches of the hand M Figure 29 Basilar joint of the thumb [ r? 54 THE HAND EXAMINATION OF SPECIFIC SYSTEMS .55 Figure 30 Collateral li gam , ' - ^ v o l a r p l ^ ^ ^ ^ . ^ figure 31 Pulleys of the digital flexor sheath; A, annular pulleys; C, cruciate pulleys 56 THE HAND mediolateral motion in extension or in flexion. The MCP' joint of the thumb is more like the hinged IP joints than the freely movable MCP joints of the fingers. At the level of the MCP joint, the flexor tendons of the digits enter a fibro-osseous tunnel referred toas the flexor sheath.. At specific sites, trie stieath is thickened by arinular fibers called pulleys (Fig. 31). The function-otthe flexor sheath is to stabilize the tendons closely against the palmar surface of the phalanges, facilitate efficient excursion of the tendons, and provide for tendon nutrition. In the.fingers,-the-A2 and-A4-pulleys-are mo'sUmportant for maintaining .the integrity of finger flexion. Without these two pulleys, the fingertip cannot be brought to the distal palmar flexion crease with normal tendor excursion. The flexor tendons and inner wall of the sheath are lined with a tissue called tenosynovium. This tissue is important in minimizing the friction of tendon excursion as well as in providing Tendon nutrition through the process of diffusion. A P A R T " 2 _ , S ^ 5 S a P R O B L E M S _ N , C A L 3 LACERATIONS One should develop a routine for examining the patient with a lacerated forearm or hand so that nerve and tendon injuries will not be overlooked. The patient who presents with a bleeding laceration of the hand should be asked to lie down. The hand is elevated, a sterile dressing is used to cover the wound, and gentle direct pressure is applied. The bleeding will usually stop within a few minutes. The practice of "clamping a bleeder" in a lacerated hand should be avoided. Previously undamaged vital structures, such as nerve or tendon, may be inadvertently crushed and irrevocably damaged in an unnecessary attempt to clamp a blood vessel. There is a tendency on the part of inexperienced physicians to look into the wound and see if nerves or tendons have been cut. However, much more can be learned on the initial examination by covering the wound and performing a gentle, systematic examination of the forearm and hand distal to the injury (Fig. 32). Each flexor tendon must be tested separately for function, and it is important to test IP function against gentle resistance. A partially cut tendon may be able to flex the finger, but it will not be able to do„so against resistanqe without causing pain. 59 I 60 THE HAND Figure 32 lamination of the lacerated hand Figure 33 Laceration of EDC over MCP joint {i.e., distal to juncturae tendinae) 62 THE HAND The position of the unsupported fingers should be noted. When the flexor tendon is completely severed, the unsupported finger restsjn extension (Fig. 32); when the extrinsic extensor tendon is completely severed, the im supported finger rests in flexion (Fig. 33). A careful distal sensory examination is then done. In the emergency room setting, especially with a frightened child, far more can be learned about the presence or absence of sensation using a light touch with a wisp of cotton than by testing sharp/dull with a pin. Only after the hand has been completely assessed by the examining physician should any anesthetic be used. In lacerations of the dorsal aspect of the MCP joint of the finger, a severed EDC will preclude active extension of thg_MCP jnint (Fig 33). Note that the intact intrinsic muscles will actively extend the IP joints in the absence of extrinsic extensor tendon function, just as the intact intrinsic muscles will actively flex the MCP joint in the absence of extrinsic flexor tendon function. A laceration over the MCP joint (knuckles) should alert the examiner to the possibility ol its naving resulted from a hjnnan^bite__or a blow apainst someAeeth. These laceTanOhiTare oT special importance because of the risk of severe infection. "^ \/\ %o\> i • A radiograph of the hand in the anteroposterior, lateral, and oblique views should be done to check for debris that may be embedded beneath the skin. Some glass is radiopaque and will therefore be shown on the film. However, some glass, wood, and plastic may not be radiopaque and may not be seen on the film. Associated fractures should be ruled out. 4 Fractures of the bones of the hand are classified by the nature and site of the fracture line and whether the fracture is closed or open (Fig. 34). An open fracture is one that communicates with the skin wound. Because of angular or rotational deformity, simple inspection of the hand will often alert the examiner that a bone or joint injury has occurred. It is important that proper anteroposterior and true lateral radiographs be obtained to confirm the presence of bony injury; the amount of angulation of the fracture may not be appreciated on improperly positioned views. A careful physical examination is essential to evaluate rotational alignment. Since the flexed fingers normally point toward the tubercle,of the scaphoid, malrotation is best evaluated by observing the fingers in tins position. The rotational alignment of the involved finger can also be compared with that of adjacent uninjured fingers by noting if the planes of the distal fingernails are parallel. It is important to realize that the deformity of fractures in the hand is due not only to the mechanism of injury but also to the deforming forces ot the musculotendinous units acting across the fracture site (Fig. 35). ' 63 » 6c FRACTURES AND DISLOCATIONS 65 T COMMON 64 THE HAND' Closed Open Midshaft E * Base 3 c ^ 2 > Dorsal angulation Volar angulation Neck Comminuted ) Hj&& Kgure 34 Fracture terminology l L Spiral Figure 35 Deforming force acting on fracture site (A) The intrinsics flex the proximal fragment of the proximal phalanx; the intrinsic flexor and extensor with longitudinal pull cause further buckling at the fracture site (B) The intrinsic muscle cuses flexion deformity of metacarpal fracture. COMMON FRACTURES AND DISLOCATIONS 67 It is apparent from the following examples that a knowledge of the functional anatomy of the soft tissues related to the joints of the hand is essential to understanding these potentially disabling injuries. The radiographs can misleadingly suggest that a very simple fracture has occurred with only a small fragment of the bone involved. This fragment, however, is often the major attachment of a collateral ligament, the volar plate, or a tendon. This small fracture may render the joint grossly or potentially unstable. Since many of these articular fractures were actually dislocations at the time of injury, the x-ray film may not indicate the true degree of original displacement that occurred. INTRA-ARTICULAR FRACTURES Particular attention should be directed to intra-articular fractures around the PIP joint (Fig. 36). These often involve injuries t o j h n vnlsr plate and portions of the collateral ligaments. The early objective evidence oTthTs may be seen radiographically as small, avulsed fragments of bone around the joint. When a volar triangular fracture fragment from the middle phalanx involves more than one quarter of the articular surface, dorsal dislocation of the middle phalanx may occur late because the volar plate and a significant portion of the collateral ligaments are attached to this small fragment. Because of this instability, these fractures often require surgical treatment. Early recognition and proper treatment depend on an awareness of the importance of these initial radiographic findings. Undertreatment is a common cause of disability. Unstable fracture-dislocation of PIP joint with volar fragment; radiographic appearance above; ligament attachments, below COMMON FRACTURES AND DISLOCATIONS 69 BENNETT'S FRACTURE Bennett's fracture is an oblique intra-articular fracture from the ulnar base of the thumb metacarpal (Fig. 37). The palmar-ulnar portion of the metacarpal, which with its heavy ligamentous attachments normally stabilizes this joint, is separated from the larger distal fragment which is displaced by the pull of the APL. FIFTH CMC FRACTURE-DISLOCATION As in the thumb, an intra-articular fracture involving the palmar articular surface of the base of the fifth metacarpal may be unstable. This occurs as a result of the joint's relative mobility and the proximal pull of the ECU, which inserts onto the dorso-ulnar base of the fifth metacarpal. BOXER'S FRACTURE "Boxer's fracture" usually involves the acute angulation of the head of the metacarpal of the small Tinger into the palfnraSThe result of a blow on the distal-dors~at*aspect of the closed fist. A loss of prominence of the metacarpal head is often seen on physical examination. The active motion of the small finger may be minimally disturbed on initial examination. F R A C T U R E O F T H E S C A P H O ID The bone most commonly fractured in the wrist is the scaphoid. There is tenderness on deep palpation in the snuff box area of the wrist just distal to the radial styloid 70 THE HAND COMMON FRACTURES AND DISLOCATIONS 71 (Fig. 38). An oblique radiograph (scaphoid view) will usually best show the fracture. Frequently the initial radiograph will fail to show the fracture, whereas repeat views of the scaphoid taken 2 weeks later mayHsEow it arter there has been resorption ot bone at the fracture, site. In alHvi'lyt Injuries with snuri box tenaerness, careful evaluation with adequate follow-up is required to make certain that these occult fractures are not overlooked. Barlii-m^ljrfa j m ^ n g is an extremely effective-means of confirming or ruling out the presence of a scaphoid fracture. The test can be performed as early as 24 hours after injury. (JjiAfcS. (DX-tLfti \xX*TTHE MCP JOINT DISLOCATION ^— The thumb may be subjected to significant hyperextension forces. The MCP volar plate may be disrupted at its metacarpal attachment with a hyperextension injury, and the joint may dislocate so that the proximal phalanx comes t o ' l i e dorsal to the metacarpal head which buttonholes between the intrinsic muscles and the FPL. Similarly, the finger MCP joint (most commonly index or small) may dislocate, with the metacarpal head becoming entrapped between the flexor tendon ulnarly, the lumbrical musculotendinous unit radially, and the volar plate dorsally. These dislocations can only be detected on true lateral radiographs and almost always require open reduction. e «ondeep p a ] p a t i o n . TORN ULNAR COLLATERAL LIGAMENT OF THE MCP JOINT O F THE THUMB Acute radial deviation of the thumb at the MCP joint may disrupt the ulnar collateral ligament. It is commonly L G4wK-it^P COMMON F ^ E S A ^ S L O C ^ O N S " COMMUN r i\™_ . , . i_ i.v.a tVmmb is caused by falls_whilR gVjvng, in which the thumb is fdrcetully radially deviated by the ski pole or strap when the hand hits the ground. It is important to compare the joint stability of the injured thumb with the patient's uninjured thumb. The lateral stress should be applied with the MCP joint in lSnETTTr^tttexlon and in full flexion. This test can be done clinically or under radiographic control. If the radial deviation of the thumb on stress testing with local wrist block anesthesia is 15° greater than that of the uninjured thumb, the collateral ligament is probably disrupted. Surgical repair is usually advisable (Fig. 39). Figure 39 Rupture of ulnar collateral ligament of the MCP joint of the thumb 5 ACQUIRED DEFORMITIES Deformities of the hand may be congenital or acquired. The acquired deformities may be associated with previous traumatic injuries to joints, tendons, or nerves, with progressively contracting fascia of the palm, or with arthritis. A discussion of some of the common deformities is presented. MALLET FINGER The mallet finger is a flexion posture or "droop" of the finger at the DIP joint area in which there is complete passive but incomplete active extension of the DIP joint (Fig. 40). The cause of the injury is usually a sudden blow to the tip of the extended finger. The jnsertinn_of l .the extensor tendon may be avulsed. or there may be an avulsion fracture of the distal phalanx with a dorsal piece of bone still attached to the extensor tendon. The PIP joint should always be examined to rule out co-existing injury. Anteroposterior and true lateral radiographs of the PD? and DIP joints are part of the examination. A laceration over the dorsum of the distal joint may sever the extensor tendon and result in a mallet finger deformity. 75 ACQUIRED DEFORMITIES 77 76 THE HAND figure 41 Boutonni&re deformity Figure 40 Malletfingerdeformity (with or without fracture) ACQUIRED DEFORMITIES 79 78 THE HAND BOUTONNTERE DEFORMITY In boutonniere deformity of the finger there is flexion of thePIP inint and hyperextension of the DIP joint (Fig. 41). It is the result of an injury or disease disrupting the extensor tendon insertion into the dorsal base of the middle phalanx. The fibers maintaining the position of the lateral bands progressively tear or stretch, allowing the lateral bands to slip volar to the axis of the PIP joint, with the result that they become flexors of the PIP. The deformity may not be present, however, immediately following the injury, but can develop over several days or weeks as the lateral bands drift progressively volarward. SWAN-NECK DEFORMITY j$frt & This deformity of the finger is one in which the PIP jnint is in hyperextension with the DIP joint in flexion (Fig. 42). It can be yeeii hi 'A variety ot conditions such as rheumatoid arthritis^certain types of spasticity, PlP joint volar plate injury, or old mallet linger deformity. CLAWHAND Claw hand deformity is manifest by flattening of the transverse metacarpal arch and longitudinal arches, with hyperextension of the MCP joints and flexion of the PEP and DIP joints (Figs. 28 and 43). The deformity is produced by an imbalance of the intrinsic and extrinsic muscles. The jntrinnignnsnips roust be markedly weakened or paralyzedAThe long extensor muscles ~Evperextend the MCP joint, and the long flexor muscles flex the PIP and DIP joints. Loss of intrinsic muscle function is L Swan-neck Figure 42 deformity sometimes referred to as an "intrinsic minus hand." This deformity can be seen in such anomalies as ulnar nerve lesions, combined median and ulnar nerve lesions, brachial"pfr icwt ~' 33 i"r ifiS r "p""*1 ^nrdjnjuries, and Charcot-Marie-Tooth disease. DUPUYTREN'S C O N T R A C T U R E Dupuytren's contracture is a confracture^aL-Uje, proliferated longitudinal hands nf the~palmar aponeurosis lying betweSn~tfre~9k4n- alUl iltSX6r tendons in the distal palm and fingers (Fig. 44). The flexor tendons are not involved. It occurs most often in the ring and small fingers. It begins as a nodule and progresses to fibrous bands, with contracture of the fingers. It is usually not painful and is most often seen in older men. It is often familial ^ S ^ O A w f V ^ M RHEUMATOID ARTHRITIS Figure 43 Claw hand deformity associated with (A) ulnar nerve palsy and (B) combined median and ulnar nerve palsy iV_ Rheumatoid arthritis in the hand usually starts with stiff, swollen, painful fingers. The MCP and PIP joints are the ones most frequently involved. Stiffness and pain are worse on arising in the morning. As the disease progresses, the digits often become deformed and the classic ulnar drift deformity of the fingers may develop (Fig. 45). Swan-neck and boutonniere deformities are common. CarpaTtunnel syndrome, trigger finger, wrist tenosynovitis, painful flexor tenosynovitis, and rupture of tendons may be present. I ACQUIRED DEFORMITIES 83 82 THE HAND Figure 45 Figure 44 Dupuytren's contracture / ^ ACQUIRED DEFORMITIES 85 Figure 46 ^eneraUvea r t h r i t J s o f t h e h a n d Figure 47 (A) Axial compression-adduction test (B) Axial compression and rotation test ACQUIRED DEFORMITIES 87 86 THE HAND DEGENERATIVE ARTHRITIS In degenerative arthritis (osteoarthritis) of the hand, the distal joints develop marginal osteophytes known as Heberden's nodes (Fig. 4fil. Similar bony lesions, called ^mirhp^'n n H e s . may occur at the_PIP joint. The MCP joints are seldom involved. The CMC joint of the thumb is also a common site for degenerative arthritis in the hand. The axial compressionadduction test (Fig. 47) is done by manipulating t h e thumb with axial compression and gentle adduction. The instability and crepitus are appreciated with the examining thumb placed on the joint and base of metacarpal. This is usually painful for the patient with joint involvement. The axial compression and rotation (Fig. 47) are often painful when the proximal phalanx is used as a lever arm for a grinding maneuver of the thumb CMC joint. DEQUERVAIN'S TENOSYNOVITIS &%\<^ A nonspecific tenosynovitis of the^Ppand^jgPB^tendons in the first_dbrsaL-wrist compartment is known as <^3eQuervain's disorders-Tenderness and crepitation may ~be presentover the radial styloid. Finlrftlfjfftjn'g test may be positive (Fig. 48). It is performed by having the patient grasp the thumb with the fingers (thumb in palm) and ulnar deviate the wrist. If this causes pain the test is positive. It is important to differentiate between deQuervain's tenosynovitis and CMC joint arthrosis of the thumb. To do this, tenderness and pain must be accurately localized between this first extensor compartment and the CMC joint of the thumb. Radiographs should be taken if there is uncertainty. Figure 4S for deQuervain's d i ^ e ACQUIRED DEFORMITIES 89 TRIGGER THUMB AND TRIGGER FINGER Stenosing tenosynovitis can occur in the thumb or any finger, but it most commonly occurs in the ring or middle fingers. Inflammation at the MCP joint pulley causes a discrepancy between the size of the tendon and pulley. The tendon may become thickened just proximal to the pulley. This discrepancy in size may cause a snapping or locking phenomenon, holding the thumb or finger flexed or extended (Fig. 49). Palpation of the flexor tendon over the MCP joint can be painfull ' " CARPAL TUNNEL SYNDROME The carpal tunnel syndrome is a median nerve compression neuropathy at the wrist where the nerve passes beneath the transverse carpal ligament (Fig. 50). Patients complain of their hands "going to sleep" and are frequently awakened at night with numbness, pain, and tingling in the thumb, index, long, and ring fingers. The small finger is not usually involved. Patients may complainof referred pain in the forearm and even as high as thfiTsEbuidec, They notice these symptoms when driving a car or during other sustained activities. The entity is more common in women than men. The dominant hand is more often involved but symptoms can be bilateral. The carpal tunnel syndrome may be associated with rheumatoid arthritis or following a TpMftg' fra^tur-p it can also be seen in a variety of medical conditions such as pregnancy, diabetes meliitus. and thyroid disease. However, most patients with the carpal tunnel syndrome have no apparent associated systemic disease. ACQUIRED DEFORMITIES 91 The hand will most often look normal; however, in long-standing cases there may be atrophy of the median innervated thenar muscles (Fig. 51). Tapping over the median nerve at the wrist crease may produce paresthesias in the hand'tTmel's signj^JFig. 52). The wrist flexion test (Phalen's test) (FigT'53fIs done by resting the elbows on a table and allowing the wrists to fall into complete volar flexion for 1 minute. If the patient has carpal tunnel syndrome, this position may produce paresthesias in the hand. If the patient is unable to flex the wrist as a result of pain or limited motion, direct compression of the median nerve can be accomplished by applying pressure with the thumb in the interval between the PL and FCR tendons at the level of the distal wrist flexion crease for 1 to 2 minutes duration. The development of discomfort or paresthesias in the distribution of the median nerve or an asymmetry in onset of symptoms when compared with the opposite wrist suggests possible carpal tunnel syndrome. CUBITAL TUNNEL SYNDROME ^ o W wu* e s ^ ^ Numbness nr paresthesias in the ring^ and small fingers of the hand suggests the possibility of entrapment neuropathy of the ulnar nerve. The ulnar nerve is susceptible to compression in the cubital tunnel at the elbow and^, , Guyon's canal at the wrist. The cubital tunnel is the fibro-osseous canal, which stabilizes the ulnar nerve as it passes behind the medial epicondyle of the humerus. There are multiple causes for injury to the ulnar nerve at this location including hypermobility or subluxation of the nerve from the cubital tunnel, and changes in the anatomic alignment of the elbow. Compression injury of the ulnar nerve within the cubital tunnel can be identified j if ACQUIRED DEFORMITIES 93 92 THE HAND Figure 52 Tinel's sign Figure 51 Atrophy of the thenar muscle l 94 ' THE HAND ACQUIRED DEFORMITIES 95 by a painful Tinel's sign and the onset of paresthesias in the ring and small fingers with elbow flexion under 2 minutes. With entrapment of the ulnar nerve at the cubital tunnel, there may be numbness over the dorsoulnar aspect of the hand in addition to paresthesias in the ring and small fingers. In more severe cases of cubital tunnel syndrome, there will be decreased 2PD in the sensory distribution of the ulnar nerve as well as muscle weakness and/or wasting of the intrinsic muscles innervated by the ulnar nerve. Clinical findings include a P"_citiyft Frrnnfint'Q tpct, wasting of the first dorsal interosseous muscle, inability to cross the index and middle fingers, and clawing of the ring and small fingers. Entrapment of the ulnar nerve at the wrist may demonstrate a positive Tinel's sign on percussion over the ulnar nerve at Guyon'sj-.anaV and"a positive Phalen's test with parestEesiaTin the ring and small fingers. It will not demonstrate loss of sensation over the dorso-ulnar aspect of the hand. Depending on the site and severity of compression, there may be diminished 2PD and/or ulnar intrinsic muscle weakness. ^ £/v ** e^ > v LATERAL EPICONDYLITIS - " f c ^ ^ ^ ~* 6 t e 6 Although sometimes referred to as tennis elbow, this condition most commonly develops in individuals who perform repetitive manual labor. The injury appears to involve a detachment of the origin of the ECRB fromjhe lateral epicondyle. THe injuryiraggravated*b"y lifting with the lorearm in a position of pronation and the wrist held in extension. Examination demonstrates point tenderness over the lateraljepiconayie. t h e patient's pain can be reproduced by having thepatient extend the wrist against resistance with the elbow held in extension and the forearm in pronation. Figure 53 s«gn (wristflexiontest) Phalen, .k I /. 6 CONGENITAL ANOMALIES Congenital defects are often encountered in the examination of the hand. These defects should be recorded in an accurate and complete manner. In the past, the use of various Greek and Latin names to describe common deficiencies has only served to confuse many clinicians. A classification should be used that groups cases according to the parts that have been affected primarily by certain embryologic failures. The various clinical pictures of limb deficiencies are felt to represent varying degrees of destruction within the ectomesenchymal mass that develops on the lateral body wall of the developing embryo. The limb bud is first noted at the fourth week after gestation. These buds grow and differentiate rapidly in a proximodistal sequence during the following four weeks. Any factor, environmental or otherwise, that disrupts the sequential differentiation during this period will produce a defect in the limb compatible with the timing of the insult. Congenital defects should be classified in the following categories as outlined by the American Society for Surgery of the Hand and the International Federation of Societies for Surgery of the Hand: 97 CONGENITAL ANOMALIES 99 98 THE HAND J /1 1. 2. 3. 4. 5. 6. 7. The deficiencies in the group reflect the separation of the pre-axial (radial) and post-axial (ulnar) divisions in the limb and include longitudinal failure of formation of the entire limb segment (phocomelias) of either radial, central, or ulnar components of the limb. An example of a segmental failure would be the phocomelia (hand attached to the trunk). This would be classified: longitudinal (L), left or right (L-R), humerus (Hu), radius (Ra), ulna (Ul). The absence of parts of the radial (pre-axial) side of the limb may vary from deficient thenar muscles to a short floating thumb, and from deficient carpals, metacarpals, and radius to the classified so-called radial club hand. The classification of longitudinal, right, radius, proximal one third, carpal partial, first ray, would be a deficiency with a partial absence of the radius and carpal bones with no thumb on the right. Central deficiencies include deficiencies of the middle three digits: index, long, and ring, and sometimes the carpal bones. The middle digit may be missing in the so-called lobster claw hand. In ulnar deficiencies, the small or ring finger may be missing and can be associated with partial or complete absence of the ulna and carpal bones. These are classified in a like manner. FAILURE OF DIFFERENTIATION (SEPARATION) OF PARTS Failure of formation of parts (arrest of development). Failure of differentiation (separation) of parts. Duplication. Overgrowth (gigantism). Undergrowth (hypoplasia). Congenital constriction band syndrome. Generalized skeletal abnormalities. FAILURE O F FORMATION OF PARTS The category of failure of formation of parts is that group of congenital deficiencies noted by failure or arrest of formation of the limb either complete or partial. This category is divided into two types: transverse and longitudinal. Transverse deficiencies Transverse deficiencies represent the so-called congenital amputations ranging from aphalangia (absence of the fingers) to amelia (absence of the extremity). The stumps are usually well-padded and may show rudimentary digits or dimpling. One of the most common defects in the group is the short below elbow amputation. This would be classified as a transverse (T), left or right (L-R), forearm (FO), upper one third deficiency. Failure of differentiation is that category in which the basic units have developed but the final form is not completed. The homogenous anlage divides into separate tissues of skeletal, dermomyofascial, or neurovascular elements found in normal limbs, but fails to differentiate Longitudinal deficiencies Longitudinal deficiencies include all other limb deficiencies in this category. In identifying longitudinal deficiencies, all completely or partially absent bones are named. i& A 100 THE HAND completely or to separate. An example in the forearm would be a synostosis (fusion of bones which are normally sflpara W ) nf the proximal radius and ulna. In the wrist, fusion of carpal bones is frequently seen as well as fusion of two or more metacarpals. Symphalangism is . end-to-end fusion of the proxiaaal-mierphalflTigpal jnjnta "^Syndactyly is by far the most common deformity seen in this category. The failure of differentiation can vary from simple skin bridging to fusion of parts. Contractures secondary to failure of differentiation of muscle, ligaments, and capsular structure are frequently seen. They vary from simple trigger thumb to flexion contractures of the small finger (camptodactyly) to the severe arthrogryposis of the hand. "*" Lateral deviation or displacement due to asymmetrical abnormalities of the digits (clmodactyly) also occurs. DUPLICATION Duplication of parts probably occurs as a result of a particular insult to the limb bud and ectodermal cap at a very early stage of their development so that splitting of the original embryonic part occurs. These defects may range from Polydactyly (too many digits) to twinning or mirror hand (duplication of the digits present). They are classified according to the parts or tissues duplicated. Polydactyly is the most common deformity seen in this group. It can be either radial (duplication of the thumb, partial or complete), central (middle three fingers) or ulnar (small finger duplication, partial or complete). The fhumrj and small finger duplications are seen more frequently. CONGENITAL ANOMALIES 101 OVERGROWTH (GIGANTISM) In this category, there can be overgrowth of the entire limb or a single part." Some cases appear to be due to skeletal overgrowth with normal-appearing soft tissue. Others show excess fat, lymphatic, and fibrous tissue; neurofibromata, lymphangiomata, or angiomata may be present in these cases. A frequently seen deformity in this category is gigantism of the digit and there can be an accompanying syndactyly. This would be classified as an overgrowth (gigantism) of the digit with syndactyly as a secondary condition. UNDERGROWTH (HYPOPLASIA) Undergrowth or hypoplasia denotes defective or incomplete development of the parts. This may be manifested in the entire extremity or its divisions. Hypoplasia may involve any of the following systems: skin and nails, musculotendinous, neurovascular, or the extremity (arm, forearm, hand). An abnormally short, completely formed metacarpal would be brachymetacarpia. Brachyphalangia refers to abnormally short middle phalanges. CONGENITAL CONSTRICTION BAND SYNDROME This abnormality involves a circumferential constriction of soft tissues of the extremity. Whether this is a rifiVfllnpmRntal riftfer.t nr mqrhanjflal rnns^rjrtirin corondary to aminiotic bands remains uncertain. Compro- 102 THE HAND mise in the development of the soft tissues distal to the site of constriction may be associated with soft tissue fusion of the distal parts, or may produce actual amputation. Those cases producing vascular compromise require surgery to maintain the viability of the affected part. 7 TUMORS GENERALIZED SKELETAL ABNORMALITIES (MADELUNG'S DEFORMITY) This congenital anomaly involves a hypoplasiaof the cHsfaTulmtund ulnar aspect of the distal radius. Itls mbre common in lemafeS than malesand is typically bilateral. The deformity may not become detectable until the child reaches adolescence. A similar deformity can sometimes be produced by infection or trauma. The most common soft, tissue mass of the hand is a ^ganglToiaijtFlM. 34). It has a well-denned, smooth"surface and is a firm cystic lesion that is fixed to the deep tissues. It may develop over the volar or dorsal area of the wrist, originating from the wrist capsule. Those in the palmriear the digital palmar skin crease arise from the flexor tendon sheatixand may or mav not be painful. Al rniir.nus cyst^js acystic lesion (actually a ganglion) o v e r t h e dorsum of the finger near the distal joint and fingernail (Fig. 55). It is associated with degenerative ajtEitiTbf, the T)fP joint of the finger and arises from the joint. It may have thin walls and there may be associated grooving of the fingernail distal to the cyst. Should a mucous cyst rupture and become infected, a septic joint may result. Other soft tissue tumors of the hand that may present as a mass are giant cell tumors of tendon sheath, pigmented villonodular synovitis, and inclusion cysts. Malignant tumors of the soft tissue and bone are rare in the hand. However, skin cancers (basal cell and squamous cell) on the dorsum of the hand are seen in the elderly. Malignant melanoma does occur in the hand and may be subungual^—IS**? KAM-ofc*/ 103 iti TUMORS 105 104 THE HAND Figure 55 Mucous cyst Figure 54 Ganglion of the hand k J 106 THE HAND Primary bone tumors of the hand usually present as swelling and/or pain in the area of the hand involved. The tumor is located radiographically and the diagnosis is established by biopsy of the tumor. The most common \L \ bone tumor of the hand is ap/epr:hop(jrnTp^lt is often first ri J Tfiscovered when a fracture "ormirs throT^h thp Ipsipn^ 8 INFECTION PARONYCHIA A paronychia is an infection of the soft tissue around the fingernail that usually begins as a "hanHnajl" and that is usually caused by arstaphylococcus jni'ection (Fig. 56A). It sgreads^ around thiT nailTepohychium, thus the term "run around." It is red, swollen, and very painful, with purulent drainage around the margin of the nail. FELON A felon is a deep infection of the pulp space of the distal segment of the finger (FigT'gSBjrThg^distal segment is swollen, red, and extremely painful. Drainage ^js usually required. It is usually caused by a staphylococcus infection and can involve the distal phalanx with osteomyelitis. PURULENT TENOSYNOVITIS Infection of the tendon sheath of the digit presents as a swollen, slightly flexed finger with tenderness over the 107 I 108 THE HAND INFECTION 109 flexor tendon sheath and increased pain on passive extension of the digit (Fig. 56C). These findings constitute if- Kanavel's four cardinal signs of a purulent tendon sheath Infection. "TFthe tendon sheath of the small finger or thumb is involved primarily, the infection may spread to the wrist area where the sheaths communicate and the classic "horseshoe" infection may develop (Fig. 57). The sheath of the index, long, and ring fingers extends to the palm but /•« not to the wrist. Streptococcus and staphylococcus are ,f]AA^ the most frequent infecting organisms. «=— $MVA*T- jof^' | These are serious infections which may extend along the flexor tendon sheath, and prompt treatment is most important. SPACE INFECTIONS g o a l ' s /a«£ cardinal signs of flexor tendon sheath infection: 1 s Mliflexign 2. Swelling 3- Tenderness over &qorJmuim sheath 4. Pain on_passive extension Figure 56 (A) Paronychia (B) Felon (CJ Flexor tendon sheath infection Thenar space and mid-palm infections are not common. When they do occur the dorsum may be more swollen than the palm of the hand. This should not mislead the examiner. The usual findings of redness, tenderness, and perhaps fluctuance help to define the abscess. The thenar space is a potential space anterior to the adductor muscle (Fig. 58). Its ulnar border is separated from the mid-palm space by a fascia arising from the metacarpal of the long finger and attaching to the palmar fascia. The mid-palm space is the potential space anterior to the interosseous muscles and posterior to the flexor tendons of the long, ring, and small fingers (Fig. 59). HO THEHAND INFECTION 111 Figure 57 Tendon sheaths of the flexor tendon Figure 58 Thenar space infection of the hand INFECTION 113 112 THE HAND H U M A N BITE INFECTIONS Human bites are commonly seen over the dorsum of the MCP joints. These usually occur when the joint area stances a toothj n a fight. The important point is that the wound may appear benign initially, but is usually inoculated with a potent mixture of bacterial flora. This is a serious injury requiring prompt treatment^ : Figure 59 Mid-palm space infection of the hand L / APPENDIX 1 KEY T O A B B R E V I A T I O N S IN THE <• ADM AdP APB APL CMC DIP ECRB ECRL ECU EDC EDM EIP EPB EPL FCR FCU FDM FDP FDS FPB FPL I IP M USED TEXT Abductor digiti minimi Adductor pollicis Abductor pollicis brevis Abductor pollicis longus Carpometacarpal Distal interphalangeal Extensor carpi radialis brevis Extensor carpi radialis longus Extensor carpi ulnaris Extensor digitorum communis Extensor digiti minimi Extensor indicis proprius Extensor pollicis brevis Extensor pollicis longus Flexor carpi radialis Flexor carpi ulnaris Flexor digiti minimi Flexor digitorum profundus Flexor digitorum superficialis Flexor pollicis brevis Flexor pollicis longus Index finger Interphalangeal Middle finger ' 115 " 6 THE HAND MCP ODM OP PIP PL R S Metacarpophalangeal Opponens digiti minimi Opponens pollicis Proximal interphalangeal Palmaris longus Ring finger Small finger APPENDIX 2 ANATOMY—SUMMARY 117 a Extension-abduction Thumb CMC Flexion-adduction Extension Finger DIP Flexion Extension Finger PIP Flexion EPL, EPB APL APB AdP Ulnar V« FPB 1st dorsal interosseous FPL None 43 Median Radial Radial Median Ulnar Ulnar or Median 9,11 15 Median, I. & M.; 6 Ulnar R. & S. Ulnar Median & Ulnar Radial Interosseous Lumbrical EDC, EIP, EDM FDP Median FDS Ulnar -Volar. Interosseous =!\ —LB .. 16,17 Ulnar Dorsal.' Interosseous Abduction i Adduction' 43 8,12, 32 Ulnar Median I. &M.; Ulnar R. & S. 8,10,13 Fig. No.f Radial EDC EIP Extension Interosseous Lumbrical Radial Ulnar ECU FCU Ulnar deviation Finger MCP Flexion Radial Median Radial Median Median Ulnar Nerve ECRL FCR FCR PL FCU ECRL ^EGRBj Prime* Muscle Radial deviation Extension Wrist Flexion Joint Control Strong DIP extension contingent upon active PIP extension control Must block FDP to detect clinical absence Intrinsic independent of MCP position: extrinsic only if MCP joint flexed or at 0° (i.e., not hyperextended) Absence—MCP extensor lag Absence—claw hand Absence—"wrist drop" : Absence—weak wrist flexion present by FDS, FDP Comments A 5 11 9 3B, 14 Fig. No.t 9 ° g HI * 3 9. o a OS a a. 3 t3 >a 3 fP CD 8 «D 2. C » CD „ O _i <= co S CO s-CDs -«• 1 OJ £ U1 n> U N M i O 0Q 5 cr « ST co CO. _. fff ^ CD K « g 00 f? CO |-« CD o- & < g 5s. 8 && 8-1*1" " BO T) r* ,-L Sfi o a t ) as u a i §;& T3 p fits; B> 3 w >—. w en on on on - < 0 2 < ^ COMM ct er1 3 sf « o C eD M 3D 3 ° C r>" O CD o 3 . vCDa. & &n: 3 ! : § RVj CD •* ftP^ S H 5 to >-» C D i CDCD n co 8 £ CB 5? &. o S' S3 CD coCD oo CO <§ S JO CO CD is H CD CD <1 CD CM 2.00 730 m i— > "13 m Z a X 00 Weak IP extension also by intrinsics ' A composite motion Comments ('achieves a given function but does not imply 'the strongest' acting across that joint) (tin addition to Figs. 19, 20, 22) Median Radial Thumb IP Flexion \ Extension FPL Radial Median Median Ulnar Radial Median Nerve Extension FPL thenar intrinsic i J muscles l - (except-OP)] EPL Supination Thumb MCP Flexion APB Radial V» FPB OP Prime* Muscle Opposition (Pronation) Joint Control INICAL APPENDIX 3 123 122 THE HAND patient's side, the elbow flexed at 90°, and the forearm and hand resting unsupported. Record and calculate posttreatment percentage relative to pre-treatment value as well as to value from the contralateral hand. Note: This is not a percentage of physical impairment or improvement but 'merely anAndicatof" of_ improving-or_wbrsening^] < condition?1 Pinch strength Use a pinch dynamometer. Key.pinch.is'the'thum^jrto radial_aspect'of middle-phalanx-of the iridexjfjngerarid is the most, universal and preferred value. Record three successive efforts and calculate percentage relative to pretreatment as well as contralateral hand values. Tip pinch value (reverse key pinch —index tip to ulnar tip of thumb) will be less powerful than key pinch. Same recordings as for key pinch. Note: This is not a percentage of physical impairment or improvement but merely an indicator of improving or worsening condition. MOTION I ' Total active motion (TAM) Sum of angles formed by MCP, PIP, and DIP joints in maximum active flexion, i.e., fist position, minus total extension deficity at the MCP, PIP, and DIP joints with active finger extension. Significant hyperextension at any joint, particularly the PIP and DIP joints, is recorded as a deficit in extension and is included in the total extension deficit. Hyperextension must be considered an abnormal value in swan-neck, (PIP) and boutonniere deformities (DIP). Comparison 6fpT^aTrdrpjSM^ea'tmentTAM.values .will be significant; however, comparison as a percentage of normal value is invalid. TAM is a term applied to one finger, and is analagous to TPM in calculation except that only active motion is recorded, not passive. 1. Suni"ofTctive"MCP"flexion"'+ 'active PlP^flexion'^ active .DIP flexion.-} 2. Minus sum of"incomplete active extension (if any is present). It is of critical importance to emphasize that this system of measuring and recording joint motions is used in the following situations: Total passive motion (TPM) Sum of angles formed by MCP, PIP, and DIP joints in maximum passive flexion minus the sum of angles of deficit from complete extension at each of these three joints: (MCP + PIP + DIP) - (MCP + PIP + DIP) = total flexion - total extensor lag TPM. 1. For a single digit 2. To indicate the total motion of that digit in degrees 3. To compare this to subsequent measurements of that same digit or the corresponding normal digit of the opposite hand in the same patient to determine if the patient is gaining or losing motion APPENDIX 3 125 12 4 THE HAND Stiff MCP + , limited PIP extension *-.* Stiff MCP + Limited PIP Extension MCP PIP DIP Totals Af^Actlve Motion (TAM) 260° - 0" = 260° Figure 60 & Active Flexion Extension Lack MCP PIP DIP Totals 0° 90° 10° 100° 0° 30° 0° 30° Total Active Motion (TAM) 100° - 30° = 70° Figure 61 "W APPENDIX 3 127 126 THE HAND It is not intended for the following: 1. To calculate a percentage of "functional improvement or loss" 2. To calculate a "percentage of impairment" Limited MCP + PIP flexion with good extension Note that some finger joints are more important than others in digital function. Furthermore, note that "function and impairment" involve many other factors as well, such as sensation. VASCULAR STATUS Patients who have vascular repair are evaluated in the following manner (not acutely, but late): 1. Examine for tissue survival.^ . _. , _ 2. Objective-evidence nf-patent vesselsJbv. Allen test and^orliltfasonic^ulse-detector. 3. ReVascularizeTil^^xaminell in resting and postexercise state by one of several methods: a. presence of capillary filling. b. physiologic testing such as ultrasonic pulse detector, skin temperatures, etc. When possible, comparison with evaluation before and after 3-minute tourniquet ischemia. 4. Evaluation regarding cold tolerance of the part. Limited MCP + PIP Flexion with Good Extension Active Flexion MCP PIP DIP Totals 70° 60° 10° 140° Extension Lack Ratings 1. Failure, no survival. 2. Poor, tissue survival. 3. Fair, objective evidence of patent vessels. 4. Good, function not limited by circulation. 5. Excellent, no cold intolerance. Total Active Motion (TAM) 140° - 0° = 140° Figure 62 W 1 INDEX Page numbers followed by f indicate figures. Abbreviation key, 115-116 Abductor pollicis longus (APL) testing, 211, 22 Allen test, 46f Anatomic variation, and nerve injury, 41 Anatomy, 47-56, 118-120 Anomalies, congenital, 97102 congenital constriction band syndrome, 101102 differentiation of parts, 99-100 duplication of parts, 100 formation of parts, 98-99 overgrowth, 101 skeletal abnormalities, 102 undergrowth, 101 Arches of hand, 52f Axial compressionadduction test, 85f Axial compression and rotation test, 85f Basilar joint of thumb, 53f Bennett's fracture, 68f, 69 ' B ^ Bones, anatomy of, 7f, 4756 Boutonniere deformity, 77f, 78 Boxer's fracture, 69 Carpal tunnel syndrome, 89, 90f Phalen's test for, 94f thenar muscle atrophy, 92f Tinel's sign, 93f Carpus, anatomy of, 47-51 Circulation, 45-47, 46f Claw hand, 78-81, 80f Congenital constriction hand syndrome, 101102 Cubital tunnel syndrome, 91 Deformities, acquired, 7595 boutonniere deformity, 77f, 78 carpal tunnel syndrome, 89, 90f claw hand, 78-81, 80f INDEX 135 134 INDEX fifth dorsal wrist Deformities (Continued) compartment, 25, 26f cubital tunnel syndrome, first dorsal wrist 89, 90f compartment, 21f, 22 degenerative arthritis, 84f, fourth dorsal wrist 85f, 86 compartment, 22, 26f deQuervain's second dorsal wrist tenosynovitis, 86, 87f compartment, 22, 23f Dupuytren's contracture, sixth dorsal wrist. compartment, 25, 27f 81, 82f lateral epicondylitis, 95 tendon arrangement, 20f mallet finger, 75, 76f third dorsal wrist rheumatoid arthritis, 81, compartment, 22, 24f Extensor pollicis brevis 83f swan-neck deformity, 78, (EPB) testing, 21f, 22 Extensor pollicis longus 79f (EPL) testing, 22, 24f trigger finger and thumb, 88f, 89 deQuervain's tenosynovitis, 86, 87f Failure of differentiation, Dislocations 99-100 fifth CMC, 69 Felon, 107, 108f MCP joint, 71 Finger motion, lOf Fingertip examination, 13, Duplication of parts, 100 Dupuytren's contracture, 81, 14f 82f Finkelstein's test, 86, 87f Flexor carpi radialis (FCR) muscle testing, 17 Flexor carpi ulnaris (FCU) Epicondylitis, lateral, 95 muscle testing, 17 Extensor carpi radialis Flexor digitorum profundus brevis (ERCB) testing, (FDP) muscle testing, 22, 23f 17, 18f Extensor carpi radialis Flexor digitorum longus (ECRL) testing, superficial (FDS) 22, 23f muscle testing, 17,19f Extensor carpi ulnaris (ECU) Flexor muscle testing, testing, 25, 27f extrinsic, 15-17. See Extensor digiti minimi also specific muscle testing, 25, 26f Flexor pollicis longus (FPL) Extensor digitorum muscle testing, 16t, 17 communis (EDC) Flexor tendon sheath testing, 22, 26f infection, 108f, HOf Extensor indicis proprius Forearm motion, lOf (EIP) testing, 22, 25, 26f Formational failures, 98-99 Extensor muscle testing, longitudinal deficiencies, extrinsic, 17-25 98-99 extrinsic extensor transverse deficiencies, 98 tightness, 25 Fractures Bennett's fracture, 68f, 69 Boxer's fracture, 69 deforming force, 65f fifth CMC, 69 intra-articular fractures, 66f, 67 scaphoid, 69-71, 70f terminology, 64f Froment's sign, 29f Ganglion of hand, 104f Gigantism, 101 Guyon's canal, 39f History, clinical, 5, 8 Hypoplasia, 101 Infection, 107-113 felon, 107, 108f paronychia, 107, 108f purulent tenosynovitis, 107-109, 108f, HOf space infections, 109, l l l f , 112f Intra-articular fractures, 66f, 67 Intrinsic muscle testing, 2534 adductor pollicis muscle, 29f, 30 hypothenar muscles, 31, 33f interosseous muscles, 3031, 32f instrinsic muscle tightness, 31, 34f lumbrical muscles, 30-31 thenar muscles, 28f, 30 Joint anatomy, 7f, 47-56 Lacerations, 59-62 of EDC over MCP joint, 61f examination, 60f Ligaments, stabilizing, 48f, 50f Madelung's deformity, 102 Mallet finger, 75, 76t Median nerve, 35, 36f sensory branches, 37, 42f Mid-palm space infection, 112f Motion joint, terminology, lOf— llf total active motion, 123127 total passive motion, 122 Mucous cyst, 105f Muscle examination, 15-34. See also specific muscle group extrinsic muscles, 15-25 intrinsic muscles, 25-34 Nailbed complex examination, 13-15,14f Nerves, 35-45 anatomic variation, 41 median nerve, 35, 36f radial nerve, 37, 40f sensibility, 43, 45 sensory branches of, 37, 41 ulnar nerve, 35-37, 38f, 39f Osteoarthritis, 84f, 85f, 86 Overgrowth, 101 Palmaris longus (PL) muscle testing, 17 136 INDEX Paronychia, 107, 108f Phalen's test, 94f Physical examination, 9, 12 anatomy of bones and joints, 47-56 circulation, 45-47 fingertip and nailbed, 1315 muscles, 15-34 nerves, 35—45 skin, 13 Pulleys of digital flexor sheath, 55f Purulent tenosynovitis, 107-109, 108f, HOf Radial nerve, 37, 40f sensory branches, 41, 42f Rheumatoid arthritis, 81, 83f Scaphoid fracture, 69-71, 70f Sensibility, 43-45, 121 two-point discrimination testing, 44f Sensory function, and nerves, 37, 41, 42f Skeletal abnormalities, 102 Skeleton of hand and wrist, 7f Skin examination, 13 Space infections, 109, l l l f , 112f Strength, 121-122 grip strength, 121-122 pinch strength, 122 Surface anatomy, 6f Swan-neck deformity, 78, 79f Terminology, 8-9 Thenar muscle atrophy, 92f Thenar space infection, 11 If Thumb motion, llf Thumb opposition test, 28f Tinel's sign, 93f Trigger thumb and finger, 88f, 89 Tumors, 103-106 ganglion, 104f mucous cyst, 105f Two-point discrimination testing, 44f Ulnar collateral ligament rupture, 71-73, 72f Ulnar nerve, 35, 37 muscles innervated by, 38f sensory branches, 41, 42f ulnar tunnel at wrist, 39f Undergrowth, 101 Vascular assessment, 17 Wrist motion, lOf